Removing a power supply

Use these instructions to remove a power supply from the Flex System Carrier-Grade chassis.

Statement 31

Electrical current from power, telephone, and communication cables is hazardous.

To avoid a shock hazard:

  • Do not connect or disconnect any cables or perform installation, maintenance, or reconfiguration of this product during an electrical storm.
  • Connect all power cords to a properly wired and grounded power source.
  • Connect to properly wired power sources any equipment that will be attached to this product.
  • When possible, use one hand only to connect or disconnect signal cables.
  • Never turn on any equipment when there is evidence of fire, water, or structural damage.
  • Disconnect the attached ac power cords, dc power sources, network connections, telecommunications systems, and serial cables before you open the device covers, unless you are instructed otherwise in the installation and configuration procedures.
  • Connect and disconnect cables as described in the following table when you install, move, or open covers on this product or attached devices.
To Connect: To Disconnect:
  1. Turn OFF all power sources and equipment that is to be attached to this product.
  2. Attach signal cables to the product.
  3. Attach power cords to the product.
    • For ac systems, use appliance inlets.
    • For dc systems, ensure correct polarity of -48 V dc connections: RTN is + and -48 V dc is -. Earth ground should use a two-hole lug for safety.
  4. Attach signal cables to other devices.
  5. Connect power cords to their sources.
  6. Turn ON all the power sources.
  1. Turn OFF all power sources and equipment that is to be attached to this product.
    • For ac systems, remove all power cords from the chassis power receptacles or interrupt power at the ac power distribution unit.
    • For dc systems, disconnect dc power sources at the breaker panel or by turning off the power source. Then, remove the dc cables.
  2. Remove the signal cables from the connectors.
  3. Remove all cables from the devices.
Attention: The following circuit breaker and ground cable ratings apply to -48 V dc power supplies only:
Breaker Listed 70 A See Note 1
Ground cable 4 AWG with Listed lug which can accept M6 ground screws See Note 2
Torque rating for ground screws 4.0 - 4.8 Newton-meters (35.4 - 42.5 inch-pounds) -
  1. The maximum steady state current of the -48 V dc power supply is less then 70 A. However during specific events, such as over subscription, it is possible for the power supply to briefly draw a current greater than 70 A. Therefore it is recommended that the power supply be protected by a Listed circuit breaker that will support up to 90 A for a minimum of 20 ms. The suggested Telect High Current Panel Dual 350A Power Distribution Panel (part number 350CB06) using the Telect 70 A circuit breakers (Part number 090-0052-0070) conforms to this specification.
  2. If not connecting to a SELV source which provides Reinforced insulation you must use a Ground Cable.
  • To maintain proper system cooling, do not operate the Flex System Carrier-Grade chassis without a power supply or power-supply filler in each power supply bay. Install a power supply or filler within 1 minute of the removal of a power supply.
  • If you are removing a functioning power supply, make sure that power LEDs on the remaining power supplies are lit and the power management policy that you have chosen supports the removal of the power supply. If the power management policy does not support removal of a power supply, shut down the operating systems and turn off all of the compute nodes before you proceed. (See the documentation that comes with the compute node for instructions for shutting down the compute node operating system and turning off the compute node.)

To remove a power supply, complete the following steps.

  1. Disconnect the power cord from the power supply.
  2. If you are removing a -48 to -60 V dc power supply, disconnect the earth ground cable from the power supply.
    1. Use a 10 mm nut driver to remove the hex nuts from the ground studs.
    2. Remove the lock washer and one flat washer from each ground stud; then, pull the ground lug off the ground studs.
    3. Place the washers and hex nuts back on the ground studs for future use.

    Illustration showing how to remove the ground cable
  3. Grasp the handle and press the release tab down.
  4. Slide the power supply out of the power-supply bay and place it on a flat, static-protective surface.

    Illustration showing the removal of a power supply

If you are instructed to return the power supply, follow all packaging instructions, and use any packaging materials for shipping that are supplied to you.